Release mechanism for preset timers



Oct. 22, 1963 c. P. CAIRELLI RELEASE MECHANISM FOR PRESET TIMERS 2 Sheets-Sheet 1 Filed Dec. 21, 1961 FIG./

INVENTOR.

' CARMEN P. CAIRELLI BY Eh WWW/@111 ATTORNEYS Oct. 22, 1963 Filed Dec. 21, 1961 FIG. 5

C. P. CAIRELLI RELEASE MECHANISM FOR PRESET TIMERS 2 Sheets-Sheet 2 CARMEN P CAIRELLI ATTORNEYS United States Patent 3,167,539 RELEASE ltdEtIi-HANESM FQR PRESET Carmen i. tlairelli, Farmington, (Conan, assignor to M. H. Rhodes, inc, Hartford, Qanta a corporation of Delaware Filed Dec. 21, wet, No. 161,197 7 Qiaims. (ill. Wi -3.54)

This invention generally relates to preset timers for controlling various types of timed operations and more particularly this invention relates to an improved release mechanism for controlling the initiation of timing movement of presettable timers.

One of the primary objects of the present invention is the provision of an improved release mechanism for use in timers of the type described wherein it will insure exact synchronization between the initiation of timing movement of the timer and initiation of the operation controlled by the timer.

A further object of the present invention is the proviion of an improved release mechanism that will successfully accomplish the above-stated objects over the life of the timer without breakdown and yet with a minimum of economically manufactured and assembled parts.

Other objects will be in part obvious and in part pointed out more in detail hereinafter.

The invention accordingly consists in the features of construction, combination of elements and arrangement of parts which will be exemplified in the construction hereafter set forth and the scope of the application which will be indicated in the appended claims.

In the drawings:

FIG. 1 is a plan view of a timer incorporating the present invention and being partially broken away to show the internal arrangement of parts with the timer set or wound for operation;

FIG. 2 is a view similar to FIG. 1 out with the timer in the operating condition;

FIG. 3 is a side elevational View of the timer in the off posit-ion and with the casing partially broken away in order to more clearly show the improved release mechanism of the present invention; and

FIG. 4 is a fragmentary perspective view of the timer showing the improved release mechanism of the present invention.

Referring to the drawings, the improved release mechanism of the present invention is shown for illustrativepurposes only as incorporated in a timer of the general type shown in United States Patent No. 2,778,418 entitled Preset Timer, issued to L. l. Lavia. assigned to the assignee of the present invention, comprising a casing Z enclosing a frame including a front plate 4 and a back plate 6 which are spaced and secured to each other by means of a suitable pillar and screw arrangement as shown in FIG. 3. Iournalled between the frame plates is a main shaft ltlof a clock movement including a spring motor 12, a gear train, of which a portion is shown at 14, and an escapement including an escape wheel 1:? and a pallet wheel 13. The motor 12 and shaft it have a clutch connection permitting winding of motor 12 and setting of the timer by rotating the shaft in a clockwise direction, as viewed in FIG. 1, by means of a manual setting knob 259 on the front of shaft 16. The clock movement is arranged to drive shaft in counterclockwise, as shown in FIG. 2 and in order to indicate the setting of the timer and the portion of the set interval remaining at any instant during the clock movement, a numbered dial 22 is provided on the casing and arranged to cooperate with a pointer on knob 2%. On the rear of the shaft is fixed a timing cam 24 which cooperates with an arm 26 pivotally mounted on the outer face of the back Patented Get. as, tee

plate 6 by a pin 28. The cam has a radial notch 39 which, when in registry with a follower 32 on the arm 26 in the off position at the expiry of the timing movement, as shown in FIG. 3, permits the arm to be pivoted clockwise (as viewed in FIGS. 1 and 2) by a spring 34 connected between the free end of the arm and the pillar 35. On the shaft adjacent cam 24 is a disc 36 of slightly smaller diameter having a limited angular lost motion connection with the cam and having a notch 38 with a sloping side by means of which follower 32 may be cammed out of notch 30 when the shaft is rotated to selectively set the timer, as shown in FIG. 1.

Control of a desired operation is effected by the timer through the provision of a control or operating cam 49 rotatably mounted on a lug il projecting from the base of the casing. By way of example only, the control cam 44 is shown as arranged to control the operation of an electric switch, and for this purpose, cam 40 is provided with a nose portion 42 arranged to engage a flexible switch contact arm 4 d carrying movable contact 46 which cooperates with a fixed contact 48, the latter being suitably attached to the base of the housing. The operating cam is biased counterclockwise, as viewed in FIGS. 1 and 2 of the drawings and in a direction to permit the contacts 46 and 48 to close by a tension spring 47 connected at one end to the operating cam and at the other end to support post 58. A notch 51 is provided in the operating cam to define a crank portion 52 whose inner peripheral surface cooperates with a stud 54 that is carried by the free end of the arm 26 to form a drive for rotating the operating cam ill clockwise to disengage the switch contacts when the arm 26 is provided into notch Si; by the spring 34 at the end of the timing cycle.

In the oil or timed out position of the timer, the stud 54 retains the operating cam 40 in its switch-opening position against the bias of tension spring 47, but when the setting knob is rotated to set the timer, as shown in FIG. 1, the follower 32 is immediately cammed out of notch 36) thereby pivoting arm 26 and moving the stud 54- counterclockwise away from its retaining relationship with respect to the operating cam 413.

In order to retain the control cam 40 in its switchopening position after the stud 54 has been moved away from the control cam upon setting of the timer, a release latch, including a plunger 64 is mounted for sliding movement between the frame plates and is biased in toward a latching position by a compression spring 62 located around the plunger and between a projecting pin 6% and the back plate 6. The plunger 6% is provided with a latching finger 66 projecting from an end thereof which, in the latching position of the plunger, extends into the path of movement of the cam crank portion, as shown in FIG. 1, and thereby prevents movement of the operating cam to switch-closing position. An operating button 7t? is mounted on the dial face for engagement with the plunger to move the plunger against the force of spring so thereby to remove the latching finger from obstructing relationship with the operating cam and permit spring 47 to move the operating cam 4-0 counterclockwise into switch-closing position wherein crank portion 52. engages stud 54.

in accordance with the present invention, the timer is provided with a novel release mechanism for controlling starting of the timing movement in exact synchronization with the closing of the switch contacts. The present mechanism also provides for stopping the mechanism when the contacts open at the end of the selected time cycle. The release mechanism includes a stop pawl mounted for pivotal movement on the back plate 6 by pin 77 and having a forwardly extending pawl or stop arm 79 and a rearwardly extending follower arm 81 as shown in V 3 FIG. 4. A tension spring 82 is attached to the extremity of the stop arm 79 and anchored to the pillar St} to thereby bias the stop arm '79 into engagement with the escapement wheel 16 between the teeth thereof to thus stop the timing movement of the gear train (as shown in FIG. 4) when the timer is set as shown in FIG. 1. The rear portion of the follower arm 81 is positioned adjacent cam arm portion 83 of the control cam 40 such that when the control cam is released for counterclockwise switch-closing movement by the plunger, the arm portion 83 will engage the follower arm Sll thereby causing pivoting of the stop pawl 75 in a clockwise direction and removal of the pawl arm 79 from its restraining relationship with the escapement wheel, as shown in FIG. 2, thereby to commence the timing movement. it is thus apparent that the release mechanism of this invention provides substantially simultaneous initiation of the timing cycle and closing of the switch contacts. At the end of the timing cycle, the driving of the operating cam clockwise by the stud 54 to thereby open the switch contacts will permit the pawl arm 79 to engage the escapement wheel thus stopping the timing movement and positioning the mechanism for the proper setting of the next timing cycle.

As seen from the foregoing description, the release mechanism of the present invention not only provides that the operation controlled by the timer will commence simultaneously with initiation of the timing movement of the timer but also provides a degree of reliability, economy of manufacture and durability hitherto unobtainable.

As will be apparent to persons skilled in the art, various modfications and adaptations of the structure above described will become readily apparent without departure from the spirit and scope of the invention, the scope of which is defined in the appended claims.

1 claim:

1. A preset timer having timing means, a movable control member for controlling the initiation of a timed operation and a release mechanism for synchronizing initial movement of the control member with initiation of the timing movement of said timing means, said release mechanism comprising a movable stop pawl engageable with said timing means to prevent movement thereof, said stop pawl having means engageable with said control member during initial movement thereof to move said stop pawl out of restraining engagement with said timing means, and a latch preventing movement of said control member, said latch being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means.

2. A'preset timer having timing means including an escapement wheel, a movable control member for controlling the initiation of a timed operation and a release mechanism for synchronizing initial movement of the control member with initiation of the timing movement of said timing means, said release mechanism comprising a stop pawl mounted for pivotal movement and having a stop arm engageable with said escapement wheel to prevent movement of said timing means, said stop pawl having a follower arm engageable with said control member during initial movement thereof to move said stop arm out of restraining engagement with said escapement wheel of said timing means, and a latch preventing movement of said cotnrol member, said latch being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means.

3. A preset timer having timing means, a control member movable to control the starting and stopping of a timed operation, means for moving the control member to stop the timed operation at the conclusion of the timing movement as determined by the timing means, and a re: lease mechanism for synchronizing initial movement of the control member with initiation of the timing movement of said timing means, said release mechanism comprising a movable stop pawl engageable with said timing means to prevent movement thereof, said stop pawl having means engageable with said control member during initial movement thereof to move said stop pawl out of restraining engagement with said timing means, and a latch preventing movement of said control member, said latch being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means.

4. A preset timer having timing means, a control member movable to control the starting and stopping of a timed operation, means for moving the control member to stop the timed operation at the conclusion of the timing movement as determined by the timing means, and a release mechanism for synchronizing initial movement of the control member with initiation of the timing movement of said timing means, said release mechanism comprising a movable stop pawl engageable with said timing means to prevent movement thereof, said stop pawl having means engageable with said control member during initial movement thereof to move said stop pawl out of restraining engagement with said timing means, a latch preventing movement of said control member and being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means, and biasing means for urging said stop pawl into engagement with said timing means at the conclusion of the timing movement.

*5. A preset timer having timing means including an escapement wheel, a control member movable to control the starting and stopping of a timed operation, means for moving the control member to stop the timed operation at the conclusion of the timing movement as determined by the'timing means, and a release mechanism for synchronizing initial movement of the control member with initiation of the timing movement of said timing means, said release mechanism comprising a stop pawl mounted for pivotal movement and having a stop arm engageable with said escapement wheel to prevent movement of said timing means, said stop pawl having a follower arm engageable with said control member during initial movement thereof to move said stop arm out of restraining engagement with said escapement wheel of said timing means, a latch preventing movement of said control member and being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means, and biasing means for urging said stop arm of said stop pawl into restraining engagement with said escapement wheel at the conclusion of the timing movement.

6. A preset timer having timing means including an escapement wheel, a control member movable to control the starting and stopping of a timed operation and having a cam arm portion, means for moving the control member to stop the timed operation at the conclusion of the timing movement as determined by the timing means, wd a release mechanism for synchronizing initial move ment of the control member with initiation of the timing movement of said timing means said release mechanism comprising a pivotally movable stop pawl having a stop arm engageable with said escapement wheel to prevent movement of said timing means, said stop pawl having a follower arm engageable with the cam arm portion of said control member during initial movement of the control member thereby to move said stop arm out of restraining engagement with the escapement wheel of said timing means, a latch preventing movement of said control member and being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of the timing means, and a spring biasing said stop pawl into restraining engagement with said escapement wheel.

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7. A preset timer having timing means including an escapement wheel, a control member having a cam arm portion and movable to control the starting and stopping of a timed operation, means for moving the control memher to stop the timed operation at the conclusion of the timing movement as determined by the timing means, and a release mechanism for synchronizing initial movement of the control member With initiation of the timing movement of said timing means, said release mechanism comprising a pivotally movable stop pawl having a stop arm, a spring biasing said stop arm into engagement with said escapement Wheel to prevent movement of said timing means, said stop pawl further having a follower arm en gageable With said cam arm portion of the control member during initial movement thereof to move said stop arm against the bias of said spring and out of restraining engagement with said escapement Wheel of said timing means, and a latch preventing movement of said control member and being releasable to permit movement of said control member and consequently said stop pawl to simultaneously initiate the timed operation and movement of 10 the timing means.

N 0 references cited. 

1. A PRESET TIMER HAVING TIMING MEANS, A MOVABLE CONTROL MEMBER FOR CONTROLLING THE INITIATION OF A TIMED OPERATION AND A RELEASE MECHANISM FOR SYNCHRONIZING INITIAL MOVEMENT OF THE CONTROL MEMBER WITH INITIATION OF THE TIMING MOVEMENT OF SAID TIMING MEANS, SAID RELEASE MECHANISM COMPRISING A MOVABLE STOP PAWL ENGAGEABLE WITH SAID TIMING MEANS TO PREVENT MOVEMENT THEREOF, SAID STOP PAWL HAVING MEANS ENGAGEABLE WITH SAID CONTROL MEMBER DURING INITIAL MOVEMENT THEREOF TO MOVE SAID STOP PAWL OUT OF RESTRAINING ENGAGEMENT WITH SAID TIMING MEANS, AND A LATCH PREVENTING MOVEMENT OF SAID CONTROL MEMBER, SAID LATCH BEING RELEASABLE TO PERMIT MOVEMENT OF SAID CONTROL MEMBER AND CONSEQUENTLY SAID STOP PAWL OF SIMULTANEOUSLY INITIATE THE TIMED OPERATION AND MOVEMEMT OF THE TIMING MEANS. 